1. Field of the Invention
The invention relates to a lever-type connector including two shaft gears.
2. Description of the Related Art
U.S. Pat. No. 5,873,745 and FIGS. 12 to 16 herein show a lever-type connector with a female housing 1F that can be connected with and separated from a male housing 1M as a lever is rotated. FIGS. 12 and 13 show the housings 1F, 1M during a connecting operation, and FIGS. 14 to 16 show the housings 1F, 1M during a separating operation. The connector of FIGS. 12 to 16 also has a lever 4. A first gear 2L is formed integrally on the lever 4 and a second gear 2R is engaged with the first gear 2L. The first gear 2L rotates with the lever 4 and causes the second gear 2R to rotate.
A first cam groove 3L is formed in the first gear 2L and a second cam groove 3R is formed in the second gear 2R. The first and second cam grooves 3L and 3R are arranged symmetrically with respect to a plane of symmetry orthogonal to a plane passing rotation shafts of the gears 2L, 2R and parallel with a connecting direction of the two housings 1F, 1M. A first cam pin 5L is engageable in the first cam groove 3L, and a second cam pin 5R is engageable in the second cam groove 3R. The cam grooves 3L, 3R have substantially the same width as the outer diameters of the cam pins 5L, 5R.
The cam pins 5L, 5R are introduced into the entrances of the cam grooves 3L, 3R, as shown in FIG. 12, at the time of connecting the housings 1F, 1M. The lever 4 then is rotated and causes the gears 2L, 2R to rotate. Surfaces of the cam grooves 3L, 3R distant from the rotation shafts engage the corresponding cam pins 5L, 5R and create a cam action that pulls the two housings 1F, 1M toward each other and into the properly connected state shown in FIG. 13.
A play or backlash 6 is set between the teeth of the gears 2L, 2R so that the gears 2L, 2R can operate smoothly operate. Rotation of the lever 4 at the start of separating the two housings 1F, 1M causes the first gear 2L to rotate clockwise by as much as the backlash 6 without causing a corresponding rotation of the second gear 2R, as shown in FIG. 14. Thus, a surface of the first cam groove 3L close to the rotation shaft engages the first cam pin 5L and only the first cam pin 5L is separated slightly. On the other hand, the second cam pin 5R has not started separating yet. Thus, the separation of the first cam pin 5L constantly precedes between the two housings 1F, 1M and the two housings 1F, 1M interfere with each other, thereby deteriorating lever operability.
Specifically, the second cam pin 5R interferes with an inner wall of the second cam groove 3R, as shown in FIG. 15, if the first cam pin 5L is arranged properly in the first cam groove 3L, and the first cam pin 5L interferes with an inner wall of the first cam groove 3L, as shown in FIG. 16, if the second cam pin 5R is arranged properly in the second cam groove 3R. In short, one of the two cam pins 5L, 5R inevitably interferes with the cam groove, and lever operability is deteriorated in either case.
The invention was developed in view of the above situation and an object thereof is to obtain good lever operability at the time of connecting and separating two housings.